Anisotropy of magnetoviscous effect in structure-forming ferrofluids

Sreekumari, A. and Ilg, P. ORCID: https://orcid.org/0000-0002-7518-5543 (2015) Anisotropy of magnetoviscous effect in structure-forming ferrofluids. Physical Review E, 92 (1). 012306. ISSN 1539-3755 doi: 10.1103/PhysRevE.92.012306

Abstract/Summary

The magnetoviscous effect, change in viscosity with change in magnetic field strength, and the anisotropy of magnetoviscous effect, change in viscosity with orientation of magnetic field, have been a focus of interest since four decades. A satisfactory understanding of the microscopic origin of anisotropy of magnetoviscous effect in magnetic fluids is still a matter of debate and a field of intense research. Here, we present an extensive simulation study to understand the relation between the anisotropy of magnetoviscous effect and the underlying change in micro-structures of ferrofluids. Our results indicate that field-induced chain-like structures respond very differently depending on their orientation relative to the direction of an externally applied shear flow, which leads to a pronounced anisotropy of viscosity. In this work, we focus on three exemplary values of dipolar interaction strengths which correspond to weak, intermediate and strong interactions between dipolar colloidal particles. We compare our simulation results with an experimental study on cobalt-based ferrofluids as well as with an existing theoretical model called the chain model. A non-monotonic behaviour in the anisotropy of magnetoviscous effect is observed with increasing dipolar interaction strength and is explained in terms of micro-structure formation.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/40567
Identification Number/DOI	10.1103/PhysRevE.92.012306
Refereed	Yes
Divisions	Science > School of Mathematical, Physical and Computational Sciences > Department of Mathematics and Statistics
Publisher	American Physical Society
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